1. Field of the Invention
The present invention relates to a hardness tester.
2. Description of Related Art
Conventionally, a hardness tester is known in which an indentation is formed by pressing an indenter into a surface of a specimen, and hardness of the specimen is measured based on dimensions of the indentation (see, for example, Related Art 1). For example, when a Vickers hardness tester is used to measure the hardness of the specimen, horizontal-direction alignment of the specimen is performed such that the formation position of the indentation in the surface of the specimen is directly below the indenter, and height-direction alignment (focusing) is performed on the formation position of the indentation. A turret is then rotated to position the indenter opposite the specimen, and a predetermined testing force is loaded on the surface of the specimen by the indenter to form the indentation. Thereafter, lengths of diagonal lines in the formed indentation are measured and the hardness is calculated based on the measured lengths of the diagonal lines in the indentation.
In such a hardness tester, an image of the surface of the specimen and of the indentation formed therein by the indenter is captured by a CCD camera and is displayed on a monitor. At this point, the image fed in from a megapixel camera (the CCD camera) has too many pixels and the full image cannot be displayed on the monitor of a size typically mounted in the hardness tester. Therefore, a method is used, for example, as shown in FIG. 9, in which pixels of a fed image G1 are dropped and an image in which the full image is scaled down (a reduced image) G2 is displayed on a monitor 81. However, in the method displaying the reduced image G2, resolution of the image suffers since pixels are dropped, and the capabilities of the CCD camera cannot be exploited. A method is known for a display method in which image resolution does not suffer, in which, for example, as shown in FIG. 10, a rectangular view B is set on top of the fed image G1 and only an image within the rectangular view B (partial image) G3 is displayed on a monitor 81. In this method, the partial image G3 displayed on the monitor 81 can be changed by displacing (scrolling) a position of the rectangular view B over the image G1.